Institute for Plant Production and Agroecology in the Tropics and Subtropics (380a)

Our expertise is on C and N cycling between plant and soil as well as flows in landscapes, including C sequestration, greenhouse gases, run-off and erosion. Innovative analytic methods (MIRS, molecular and isotope techniques) complement modelling at plot and landscape level. Modelled scenarios integrate social (including indigenous) and biophysical knowledge domains to simulate management and land use scenarios.

WaNuLCAS, a plot-scale agroforestry model, simulates competition of intercropped plants for light, water and nutrients. The Land Use Change Impact Assessment (LUCIA, developed by our group) is a dynamic spatially explicit model for small watersheds. It allows testing impacts of land use change (position of different land cover types in a watershed) and management options (manure, fertiliser application, burning, ploughing etc) on natural resources such as soil and vegetation carbon stocks, soil water balance, erosion, nutrient stocks in soils and availability to plants and yields, among others. LUCIA can be coupled to socio-economic models or use own tools to simulate land use scenarios taking farmers’ decision rules into account.

We contribute to the consortium through improved plot- and landscape-scale models, simulating consequences of resource management (e.g. organic inputs and farmers’ practices) for ecosystem services (C sequestration, soil water, erosion) and food security (productivity) at plot and landscape level. At plot level, residue management will change C and N cycling and productivity, soil water holding capacity, water use efficiency, infiltration / runoff, erosion and sedimentation downstream. Interactions at landscape scale lead to changes in spatial patterns of vegetation/cropping areas and their functional attributes.

Simulations will integrate field data and outputs will form the baseline for further scenario modelling: Data on topography, soil and land cover will be provided by 2.1, information on organic amendments by 1.2 and on management practices by 3.2. Model outputs will be evaluated by stakeholders (3.2) and used for scenario modelling across scales (2.3).

We have been involved in SOM research in Kenya (long-term trials with Kenyatta and FiBL) since several years. ERAfrica will provide the opportunity to expand our network and compare effects across sites.